Field of the Invention
[0001] The present invention relates to a fluid flow regulating valve, and more particularly,
to a fluid flow regulating valve using a thermal expansion material which can precisely
regulate the flow of large and small amounts of fluid.
Description of the Prior Art
[0002] A conventional flow regulating valve using a thermal material is disclosed in US
patent No.4943032 and an example thereof is shown in the accompanying Figure 10 of
the present application as comprising a first silicon wafer 12,a Pyrex wafer 22 attached
on an upper side of the first silicon wafer 12, and a second silicon wafer 30 attached
on a lower side of the first silicon wafer 12. A chamber 10 for receiving a thermal
expansion material is etched in the first silicon wafer 12 and a cavity for receiving
a heater 21 is etched in an area between the chamber 10 and the Pyrex wafer 22. A
thickness (h) is provided in an area 12a between the first silicon wafer 12 and the
chamber 10 etched therein which is extremely thin, i.e. only a few µm. Also, a slot
44 for allowing the flow of fluid is formed in an area where the first silicon wafer
12 and the second silicon wafer 30 are attached, and a nozzle 32 is etched in the
second silicon wafer 30 at a location next to the area 12a under the chamber 10.
[0003] With regard to the operation of the above fluid regulator, when light is supplied
to the Pyrex wafer 22 through a light pipe 19 or when the heater 21 is operated, the
material contained in the chamber 10 expands. This causes the area 12a of the first
silicon wafer 12 to expand, as it is the thinnest part thereof, in a direction toward
the nozzle 32. As a result, fluid entering through inlet port 46 travels along the
indicated path to the nozzle 32 through the slot 44 which is regulated according to
the degree of expansion of the area 12a under the chamber 10.
[0004] In the above prior art valve, the heater 21, chamber 10, and slot 44 are either etched
or go through a microscopic silicon process such as a photographic process. However,
these processes require the use of very expensive equipment.
[0005] Also, the microscopic silicon process is a technique used for valves that regulate
only a small flow of fluid. Valves manufactured by this process are used in medical
instruments, environmental analysis instruments and the like. As a result, the application
of valves made using this process is limited.
[0006] To regulate a large flow of fluid, the capacity of both the silicon wafer and the
Pyrex wafer for each valve needs to be enlarged. However, this greatly increases manufacturing
costs.
[0007] Furthermore, since the diameters of the inlet and outlet ports and the slot are processed
to have minute dimensions, foreign substances contained in the fluid can easily block
passages thereby deteriorating the reliability of the products.
[0008] It is an object of the present invention therefore to solve or substantially reduce
the above described problems.
[0009] It is a further object of the present invention to provide a fluid flow regulating
valve which can precisely regulate both small and large flows of fluid, and which
is particularly suitable for use in regulating coolant flow in refrigerators or air
conditioners.
[0010] It is another object of the present invention to provide a fluid flow regulating
valve which is inexpensive.
[0011] According to the present invention, there is provided a fluid flow regulating valve
comprising:
a body provided with inlet and outlet ports;
a displacement control part in said body, said displacement control part containing
the thermal expansion material and being displaced towards the outlet port when the
thermal expansion material expands, thereby regulating the degree of opening of the
outlet port; and
heating means for heating the thermal expansion material within the displacement control
part.
[0012] Preferably, the heating means comprises a heater and the displacement control part
comprises adiabatic means for preventing heat of the thermal expansion material heated
by the heater from being discharged to environment.
[0013] According to one embodiment of the present invention, said adiabatic means is made
of adiabatic material covered on the displacement control part.
[0014] According to another embodiment, said adiabatic means comprises a separating member
disposed between the heater and the displacement control part so as to prevent the
heater from directly contacting the displacement control part.
[0015] According to a still further embodiment, the displacement control part comprises
a container containing the thermal expansion material, said container being coupled
to the body and an expansion plate for regulating the degree of opening of the outlet
port by being expanded in accordance with an expansion of the thermal expansion material,
said expansion plate being hermetically coupled to the container.
[0016] The container preferably comprises a supporting plate coupled to the body and an
annular wall or compartment hoop, one end of which is attached on the supporting plate
while the other end of which is attached on the expansion plate, thereby defining
a space for containing the thermal expansion material.
[0017] According to yet another embodiment, the displacement control part comprises a supporting
plate coupled to the body and an expansion cover for regulating the degree of opening
of the outlet port by being expanded according to an expansion of the thermal expansion
material, said expansion cover being attached on the supporting plate to define a
space for containing the thermal expansion material.
Brief description of the drawings
[0018] A more complete appreciation of this invention, and many of the advantages thereof,
will become more readily apparent with reference to the following detailed description
of several preferred embodiments, by way of example only, with reference to the accompanying
drawings, in which:
Figure 1 is an exploded perspective view illustrating a flow regulating valve according
to a first embodiment of the present invention;
Figure 2 is a sectional view taken along line III-III of Figure 1 when the valve is
assembled;
Figure 3 is a sectional view illustrating a flow regulating valve according to a second
embodiment of the present invention;
Figure 4 is a sectional view illustrating a flow regulating valve according to a third
embodiment of the present invention;
Figure 5 is a sectional view illustrating a flow regulating valve according to a fourth
embodiment of the present invention;
Figure 6 is a sectional view illustrating a flow regulating valve according to a fifth
embodiment of the present invention;
Figure 7 is a sectional view illustrating a flow regulating valve according to a sixth
embodiment of the present invention;
Figure 8 is a sectional view illustrating a flow regulating valve according to a seventh
embodiment of the present invention;
Figure 9A is a sectional view illustrating a flow regulating valve according to an
eighth embodiment of the present invention;
Figure 9B is an enlarged view illustrating the circled portion "P" of Figure 9A; and
Figure 10 is a view showing a prior art fluid flow regulating valve.
Detailed description of the preferred embodiments
[0019] Reference will now be made in detail to the preferred embodiments of the invention,
examples of which are illustrated in the accompanying drawings. Wherever possible,
the same reference numerals will be used throughout the drawings to refer to the same
or like parts.
[0020] Referring to Figures 1 and 2, there is shown a flow regulating valve 100 which comprises
a body 110, displaceable control means in the form of a displacement control part
120 containing a thermal expansion material 125. The thermal expansion material 125
expands when it is heated by the heating member 130. When the thermal expansion material
125 expands, a side of the displacement control part 120 expands to block outlet port
112, thereby regulating the amount of fluid discharged.
[0021] In more detail, the body 110 comprises an upper body 110a and a lower body 110b coupled
thereto with an enclosed space defined between the upper and lower bodies 110a and
110b. The upper body 110a is provided with an inlet port 111 through which fluid enters
the valve 100 and the outlet port 112 through which the fluid is discharged. The outlet
port 112 protrudes from the inside surface of the upper body 110a so that it can be
disposed closer to the displacement control part 120. A terminal 113 is provided in
the lower body 110b and connects power supply 160 to the heating member 130.
[0022] The displacement control part 120 comprises a container 121 for the thermal expansion
material and an expansion plate 122 coupled to the container 121.
[0023] The container 121 shown in Figures 1 and 2, includes a supporting plate 121a coupled
to the lower body 110b and an annular member in the form of a compartment hoop 121b
attached on the supporting plate 121a and defining a space in which the thermal expansion
material 125 is contained. The expansion plate 122 is provided on the annular member
hoop 121b. As shown in Figure 3 illustrating a second embodiment of the present invention,
the container 121 can be formed as an integral body defining a space 123 within which
the thermal expansion material 125 is contained.
[0024] Referring again to Figure 2, the expansion plate 122 is attached on the annular member
121b so that it is positioned opposite the outlet port 112.
[0025] The expansion plate 122 expands when the thermal expansion material 125 expands.
It is preferable that the supporting plate 121a, the annular member 121b, and the
expansion plate 122 are attached to each other using acrylic resin or by brazing.
[0026] When the thermal expansion material contained within the space 123 is heated, pressure
within the space 123 is increased by gas generated from the thermal expansion material
125. At this point, since the thermal expansion material 125 is enclosed within the
airtight space 123, the expansion plate 122 is expanded or displaced due to the increase
in pressure and the expansion plate 122 expands toward the outlet port 122, and, consequently,
comes into contact with it and closes it.
[0027] As the clearance between the outlet port 112 and the expansion plate 112 can be varied,
so the amount of fluid exhausted through the outlet port 112 can also be varied. By
regulating the voltage applied to the heating member 130, the amount of fluid exhausted
through the outlet port 112 can be regulated. For instance, when a large voltage is
applied to the heating member 130, the expansion plate 122 is expanded and reduces
the size of the outlet port 112, thereby allowing only a small amount of fluid to
be exhausted. The body 110 functions as a passage through which the fluid flows, while
the expansion plate 122 functions as a regulator for regulating a sectional area of
the passage.
[0028] Formed through the supporting plate 121a are injection ports 124 through which the
thermal expansion material can be injected into the space 123. After hermetically
enclosing the space 123 with the supporting plate 121a, the annular wall 121b and
the expansion plate 122, the thermal expansion material 125 is injected into the space
123 through the injection ports 124. Preferably, the thermal expansion material is
a fluorine composition which is expandable at a relatively low temperature and does
not easily react to or with other materials.
[0029] The heating member 130 is mounted within the displacement control part 120 and includes
a heater 131 which generates heat when a voltage is applied thereto from an electric
power source 160. The heater 131 is electrically connected to the terminal 113 by
electric wire 132a, and the terminal 113 is electrically connected to the electric
power source 160 by another wire 132b, thereby allowing the application of a voltage
to the heater 131. The electric wire 132a passes through a contacting portion of the
supporting plate 121a and the annular wall 121b as shown in Figure 2, or passes through
the injection port 124 formed on the container 121 as shown in Figure 3.
[0030] Preferably, the displacement control part is made of material selected from the group
consisting of metal and ceramic, both of which have high pressure-resistance characteristics.
[0031] Figures 4 and 5 show third and fourth embodiments of the present invention, respectively.
The fluid flow regulating valves in these embodiments may have adiabatic means which
can prevent heat generated by the heater 131 from being discharged into the environment.
[0032] An adiabatic material 151 may be deposited or coated on the whole outer surface of
the displacement control part 120 as shown in Figure 4, or deposited or coated on
only the expansion plate 122 as shown in Figure 5, if the supporting plate 121a and
the compartment hoop 121b are formed having thicknesses sufficient to retain heat.
[0033] As described above, since the adiabatic member 150 is provided on the displacement
control part 120, heat generated by the heater 131 cannot be discharged to the environment.
[0034] Figure 6 shows a fifth embodiment of the present invention in which a separating
member 152 is provided as the adiabatic means between the heater 131 and the supporting
plate 121a so that heat cannot directly contact the supporting plate 121a. Since the
separating member 152 is disposed between the heater 131 and the container 121, any
heat generated from the heater 131 cannot be directly transmitted to the supporting
plate 121a, thereby obtaining an adiabatic effect.
[0035] If a large difference in temperature between fluid directed to the body 110 and the
displacement control part 120 results, since heat exchange between the fluid and the
displacement control part 120 occurs, the amount of expansion of the expansion plate
122 cannot be precisely controlled. To prevent this, Figure 7 shows a sixth embodiment
of the present invention in which an auxiliary expansion plate 128 is provided between
the inlet and outlet ports 111 and 112. The auxiliary expansion plate 128 is connected
to the expansion plate 122 by a connecting member 129 and expands as much as the expansion
plate 122. Therefore, when the expansion plate 122 expands, the opening of the outlet
port 112 is regulated by the auxiliary expansion plate 128.
[0036] Figure 8 shows a seventh embodiment of the present invention in which the supporting
plate 121a is coupled to the lower body 110b, and an expansion cover 127 is coupled
to the supporting plate 121a. The expansion cover 127 functions as the annular wall
121b and the expansion plate 122 of the preceding embodiments. The thermal expansion
material 125 is contained in the space defined between the expansion cover 127 and
the supporting plate 121a, so that when the thermal expansion material expands, the
expansion cover 127 also expands to regulate the opening of the outlet port 112. The
expansion cover 127 is bellows-shaped so that expansion of the cover 127 can be rapid
and precise in response to expansion of the thermal expansion material. Further, the
lower body 110b disposed between the terminal 113 and the inlet port 124 is provided
with an electrode plate 135 to connect the terminal 113 to the heater 131.
[0037] Figures 9A and 9B illustrate an eighth embodiment of the present invention in which
the valve is designed to place the inlet port 115a in communication with the outlet
port 116a from a normal closed position thereof.
[0038] As in the preceding embodiments, the body 110 comprises the upper and lower bodies
110a and 11b. The upper body 110a is provided with the inlet and outlet ports 115a
and 116a. Inlet and outlet tubes 115b and 116b respectively pass through the inlet
and outlet ports 115a and 116a.
[0039] Terminal 113 is provided on the lower body 110b and the container 121 has heater
131 attached on the upper surface of the lower body 110b. Attached on the upper surface
of the container 121 is the expansion plate 122 for hermetically enclosing the space
defined by the container 121.
[0040] Provided on the expansion plate 122 is a valve member 170 for selectively placing
the inlet port 115a and the outlet port 116 in communication with each other. The
valve member 170 comprises a sleeve 171 supported by the inlet and outlet tubes 115b
and 116b and a spool 175 for selectively placing the inlet tube 115b and the outlet
tube 116b in communication with each other while reciprocating in accordance with
the degree of the expansion of the expansion plate 122.
[0041] Formed through the sleeve 171 are inlet and outlet passages 171a and 171b (see Figure
9B). The inlet passage 171a communicates with the outlet passage 171b through hollow
portion 171c of the sleeve 171. The inlet and outlet tubes 115b and 116b are inserted
into the inlet and outlet passages 171a and 171b, respectively. With this structure,
the sleeve 171 is supported by the inlet and outlet tubes 115b and 116b. An exhaust
hole 172 is formed on a portion of the sleeve above the inlet and outlet passages
171a and 171b which allows the spool 175 to smoothly reciprocate by preventing a vacuum
being formed in the space defined between the sleeve 171 and the spool 175.
[0042] One end of the spool 175 is inserted into the hollow portion 171c, while the other
end is coupled to the expansion plate 122. Therefore, when the expansion plate 122
is displaced toward the sleeve 171 by the expansion of the thermal expansion material,
the spool 175 rises, and when the thermal expansion material is returned to its initial
condition, the spool 175 returns to its initial portion. The upper end of the spool
175 is positioned above the inlet and outlet passages 171a and 171b. A communicating
passage 176 is formed at an appropriate position such that the inlet passage 171a
is disconnected with the outlet passage 171b in the normal closed position of the
spool 175, while the inlet passage 171a communicates with the outlet passage 171b
in the raised position of the spool 175. The communicating area of the inlet and outlet
passages 171a and 17b is therefore varied according to how high the spool 175 rises,
thereby regulating the amount of the fluid. The spool 175 is connected to the expansion
plate 122 by a connecting member 178.
1. A fluid flow regulating valve comprising a body provided with inlet and outlet ports
characterised by displaceable control means in said body containing a thermally expandable material
and displaceable towards the outlet port when the thermal expandable material expands,
thereby regulating the degree of opening of said outlet port and heating means for
heating the thermal expansion material located within the displaceable control means
for heating the thermally expandable material.
2. A fluid flow regulating valve according to claim 1 characterised in that the heating
means comprises a heater and the displaceable control means comprises adiabatic means
for preventing heat generated by the thermally expandable material when heated by
the heater from being discharged to the ambient environment.
3. A fluid flow regulating valve according to claim 2 characterised in that said adiabatic
means is made of an adiabatic material which covers the displaceable means.
4. A fluid flow regulating valve according to claim 2 characterised in that said adiabatic
means comprises a separating member disposed between the heater and the displaceable
control means to prevent the heater from directly contacting said displaceable means.
5. A fluid flow regulating valve according to claim 1 characterised in that the displaceable
control means comprises a container for the thermally expandable material coupled
to the body and an expansion plate for regulating the degree of opening of the outlet
port by being expanded in accordance with an expansion of the thermally expandable
material, said expansion plate being hermetically coupled to the container.
6. A fluid flow regulating valve according to claim 5 characterised in that the container
comprises a supporting plate coupled to the body and an annular member one end of
which is attached to the supporting plate while the other end is attached on the expansion
plate, thereby defining a space for containing the thermally expandable material.
7. A fluid flow regulating valve according to claim 1 characterised in that the displaceable
control means comprises a supporting plate coupled to the body and an expansion cover
for regulating the degree of opening of the outlet port by being expanded according
to an expansion of the thermally expandable material, said expansion cover being attached
to the supporting plate to define a space for containing the thermally expandable
material.
8. A fluid flow regulating valve according to claim 7 characterised in that said expansion
cover is bellows-shaped and can precisely and rapidly respond to the expansion of
the thermally expandable material.
9. A fluid flow regulating valve according to claim 5 or 7 characterised in that the
supporting plate is provided with an injection hole for injection of the thermally
expandable material into the displaceable control means.
10. A fluid flow regulating valve according to claim 1 further characterised by an auxiliary
expansion plate for regulating the degree of opening of the outlet port by being expanded
as much as the expansion plate and for preventing heat exchange between fluid directed
onto the body and the displacement control part.
11. A fluid flow regulating valve as claimed in claim 1 characterised by movable communicating
control means for communicating or disconnecting the inlet and outlet ports with each
other when the displaceable control means is displaced.
12. A fluid flow regulating valve according to claim 11 characterised in that the displaceable
control means comprises a supporting plate coupled to the body, a wall defining a
compartment attached to the supporting plate for defining a space to contain the thermally
expandable material and an expansion plate attached to the wall, said expansion plate
expanding when the thermally expandable material expands.
13. A fluid flow regulating valve according to claim 12 characterised in that the supporting
plate is provided with an injection hole for the injection of the thermally expandable
material into the displaceable control means.
14. A fluid flow regulating valve according to claim 11 further characterised by inlet
and outlet tubes respectively inserted into the inlet and outlet ports, wherein said
communicating control means comprises a sleeve having inlet and outlet passages therein
respectively connectable to the inlet and outlet tubes for selectively placing the
inlet and outlet tubes in communication with each other, said sleeve being supported
by the inlet and outlet tubes and a spool having a first end coupled to the displaceable
control means and a second end inserted into the sleeve, said spool being movable
such that the outlet passage therein can be selectively placed in communication with
the inlet passage.
15. A fluid flow regulating valve according to claim 14 characterised in that the sleeve
is provided with an exhaust hole for preventing a vacuum being formed in a space within
the sleeve.
16. A fluid flow regulating valve according to claim 15 wherein the spool is provided
with a communicating hole for connecting the inlet passage to the outlet passage.